1. Field of the Invention
The present invention relates to an electric power control apparatus for a construction machine.
2. Description of the Background Art
Conventionally, there is known a construction machine provided with an electrical storage device to use electric power stored in the electrical storage device as drive source. For instance, Japanese Unexamined Patent Publication No. 2002-325379 (patent literature 1) in FIG. 4 discloses a technology of setting the upper limit of charge electric power and the upper limit of discharge electric power of an electrical storage device in accordance with the temperature (a representative temperature) of the electrical storage device.
There is an electrical storage device including a plurality of electrical storage modules. On the other hand, the internal temperature of an electrical storage device may vary depending on the cooling method or the warm-up method of the electrical storage device. Therefore, in the electrical storage device including the plurality of electrical storage modules, there can be a case where temperature difference occurs between the electrical storage modules. In this case, if the upper limit of charge electric power and the upper limit of discharge electric power of the electrical storage device are set based on the representative temperature of the electrical storage device, as disclosed in the technology of patent literature 1, a drawback may occur resulting from an improper temperature of a specific electrical storage module. Specifically, if there is an electrical storage module of a temperature lower than the representative temperature of the electrical storage device at the time of charge/discharge with respect to the electrical storage device, an over-voltage may occur in the electrical storage module. On contrary, if there exists an electrical storage module of a temperature higher than the representative temperature of the electrical storage device, the electrical storage module may be over-heated.